which may be the objects of our reasoning. The conception always
precedes the understanding; and where the one is obscure, the other is
uncertain; where the one fails, the other must fail also.
Secondly, It is certain that this repetition of similar objects in
similar situations produces nothing new either in these objects, or
in any external body. For it will readily be allowed, that the several
instances we have of the conjunction of resembling causes and effects
are in themselves entirely independent, and that the communication
of motion, which I see result at present from the shock of two
billiard-balls, is totally distinct from that which I saw result from
such an impulse a twelve-month ago. These impulses have no influence
on each other. They are entirely divided by time and place; and the one
might have existed and communicated motion, though the other never had
been in being.
There is, then, nothing new either discovered or produced in any objects
by their constant conjunction, and by the uninterrupted resemblance
of their relations of succession and contiguity. But it is from this
resemblance, that the ideas of necessity, of power, and of efficacy, are
derived. These ideas, therefore, represent not anything, that does or
can belong to the objects, which are constantly conjoined. This is
an argument, which, in every view we can examine it, will be found
perfectly unanswerable. Similar instances are still the first source
of our idea of power or necessity; at the same time that they have no
influence by their similarity either on each other, or on any external
object. We must, therefore, turn ourselves to some other quarter to seek
the origin of that idea.
Though the several resembling instances, which give rise to the idea of
power, have no influence on each other, and can never produce any new
quality in the object, which can be the model of that idea, yet the
observation of this resemblance produces a new impression in the mind,
which is its real model. For after we have observed the resemblance in
a sufficient number of instances, we immediately feel a determination of
the mind to pass from one object to its usual attendant, and to conceive
it in a stronger light upon account of that relation.
This determination
is the only effect of the resemblance; and therefore must be the same
with power or efficacy, whose idea is derived from the resemblance. The
several instances of resembling conjunctions lead us into the notion of
power and necessity. These instances are in themselves totally distinct
from each other, and have no union but in the mind, which observes
them, and collects their ideas. Necessity, then, is the effect of this
observation, and is nothing but an internal impression of the mind,
or a determination to carry our thoughts from one object to another.
Without considering it in this view, we can never arrive at the most
distant notion of it, or be able to attribute it either to external or
internal objects, to spirit or body, to causes or effects.
The necessary connexion betwixt causes and effects is the foundation of
our inference from one to the other. The foundation of our inference is
the transition arising from the accustomed union. These are, therefore,
the same.
The idea of necessity arises from some impression. There is no
impression conveyed by our senses, which can give rise to that idea. It
must, therefore, be derived from some internal impression, or impression
of reflection. There is no internal impression, which has any relation
to the present business, but that propensity, which custom produces, to
pass from an object to the idea of its usual attendant.
This therefore
is the essence of necessity. Upon the whole, necessity is something,
that exists in the mind, not in objects; nor is it possible for us ever
to form the most distant idea of it, considered as a quality in bodies.
Either we have no idea of necessity, or necessity is nothing but that
determination of the thought to pass from causes to effects, and from
effects to causes, according to their experienced union.
Thus as the necessity, which makes two times two equal to four, or three
angles of a triangle equal to two right ones, lies only in the act of
the understanding, by which we consider and compare these ideas; in like
manner the necessity or power, which unites causes and effects, lies
in the determination of the mind to pass from the one to the other. The
efficacy or energy of causes is neither placed in the causes themselves,
nor in the deity, nor in the concurrence of these two principles; but
belongs entirely to the soul, which considers the union of two or more
objects in all past instances. It is here that the real power of causes
is placed along with their connexion and necessity.
I am sensible, that of all the paradoxes, which I, have had, or shall
hereafter have occasion to advance in the course of this treatise, the
present one is the most violent, and that it is merely by dint of solid
proof and reasoning I can ever hope it will have admission, and overcome
the inveterate prejudices of mankind. Before we are reconciled to this
doctrine, how often must we repeat to ourselves, that the simple view of
any two objects or actions, however related, can never give us any idea,
of power, or of a connexion betwixt them: that this idea arises from
the repetition of their union: that the repetition neither discovers nor
causes any thing in the objects, but has an influence only on the mind,
by that customary transition it produces: that this customary transition
is, therefore, the same with the power and necessity; which are
consequently qualities of perceptions, not of objects, and are
internally felt by the soul, and not perceivd externally in bodies?
There is commonly an astonishment attending every thing extraordinary;
and this astonishment changes immediately into the highest degree
of esteem or contempt, according as we approve or disapprove of the
subject. I am much afraid, that though the foregoing reasoning appears
to me the shortest and most decisive imaginable; yet with the generality
of readers the biass of the mind will prevail, and give them a prejudice
against the present doctrine.
This contrary biass is easily accounted for. It is a common observation,
that the mind has a great propensity to spread itself on external
objects, and to conjoin with them any internal impressions, which they
occasion, and which always make their appearance at the same time that
these objects discover themselves to the senses. Thus as certain sounds
and smells are always found to attend certain visible objects, we
naturally imagine a conjunction, even in place, betwixt the objects and
qualities, though the qualities be of such a nature as to admit of no
such conjunction, and really exist no where. But of this more fully
hereafter [Part IV, Sect. 5.]. Mean while it is sufficient to observe,
that the same propensity is the reason, why we suppose necessity and
power to lie in the objects we consider, not in our mind that considers
them; notwithstanding it is not possible for us to form the most distant
idea of that quality, when it is not taken for the determination of the
mind, to pass from the idea of an object to that of its usual attendant.
But though this be the only reasonable account we can give of necessity,
the contrary notion if; so riveted in the mind from the principles
above-mentioned, that I doubt not but my sentiments will be treated by
many as extravagant and ridiculous. What! the efficacy of causes lie
in the determination of the mind! As if causes did not operate entirely
independent of the mind, and would not continue their operation,
even though there was no mind existent to contemplate them, or reason
concerning them. Thought may well depend on causes for its operation,
but not causes on thought. This is to reverse the order of nature, and
make that secondary, which is really primary, To every operation there
is a power proportioned; and this power must be placed on the body, that
operates. If we remove the power from one cause, we must ascribe it to
another: But to remove it from all causes, and bestow it on a being,
that is no ways related to the cause or effect, but by perceiving them,
is a gross absurdity, and contrary to the most certain principles of
human reason.
I can only reply to all these arguments, that the case is here much the
same, as if a blind man should pretend to find a great many absurdities
in the supposition, that the colour of scarlet is not the same with the
sound of a trumpet, nor light the same with solidity. If we have really
no idea of a power or efficacy in any object, or of any real connexion
betwixt causes and effects, it will be to little purpose to prove, that
an efficacy is necessary in all operations. We do not understand our own
meaning in talking so, but ignorantly confound ideas, which are entirely
distinct from each other. I am, indeed, ready to allow, that there may
be several qualities both in material and immaterial objects, with which
we are utterly unacquainted; and if we please to call these POWER or
EFFICACY, it will be of little consequence to the world.
But when,
instead of meaning these unknown qualities, we make the terms of power
and efficacy signify something, of which we have a clear idea, and which
is incompatible with those objects, to which we apply it, obscurity
and error begin then to take place, and we are led astray by a false
philosophy. This is the case, when we transfer the determination of the
thought to external objects, and suppose any real intelligible connexion
betwixt them; that being a quality, which can only belong to the mind
that considers them.
As to what may be said, that the operations of nature are independent
of our thought and reasoning, I allow it; and accordingly have observed,
that objects bear to each other the relations of contiguity and
succession: that like objects may be observed in several instances to
have like relations; and that all this is independent of, and antecedent
to the operations of the understanding. But if we go any farther, and
ascribe a power or necessary connexion to these objects; this is what
we can never observe in them, but must draw the idea of it from what we
feel internally in contemplating them. And this I carry so far, that I
am ready to convert my present reasoning into an instance of it, by a
subtility, which it will not be difficult to comprehend.
When any object is presented to us, it immediately conveys to the mind
a lively idea of that object, which is usually found to attend it; and
this determination of the mind forms the necessary connexion of these
objects. But when we change the point of view, from the objects to the
perceptions; in that case the impression is to be considered as the
cause, and the lively idea as the effect; and their necessary connexion
is that new determination, which we feel to pass from the idea of the
one to that of the other. The uniting principle among our internal
perceptions is as unintelligible as that among external objects, and
is not known to us any other way than by experience. Now the nature
and effects of experience have been already sufficiently examined and
explained. It never gives us any insight into the internal structure or
operating principle of objects, but only accustoms the mind to pass from
one to another.
It is now time to collect all the different parts of this reasoning,
and by joining them together form an exact definition of the relation of
cause and effect, which makes the subject of the present enquiry. This
order would not have been excusable, of first examining our inference
from the relation before we had explained the relation itself, had it
been possible to proceed in a different method. But as the nature of the
relation depends so much on that of the inference, we have been obliged
to advance in this seemingly preposterous manner, and make use of terms
before we were able exactly to define them, or fix their meaning. We
shall now correct this fault by giving a precise definition of cause and
effect.
There may two definitions be given of this relation, which are only
different, by their presenting a different view of the same object,
and making us consider it either as a philosophical or as a natural
relation; either as a comparison of two ideas, or as an association
betwixt them. We may define a CAUSE to be An object precedent and
contiguous to another, and where all the objects resembling the former
are placed in like relations of precedency and contiguity to those
objects that resemble the latter. I If this definition be esteemed
defective, because drawn from objects foreign to the cause, we may
substitute this other definition in its place, viz. A CAUSE is an object
precedent and contiguous to another, and so united with it, that the
idea, of the one determines the mind to form the idea of the other, and
the impression of the one to form a more lively idea of the other. 2
should this definition also be rejected for the same reason, I know no
other remedy, than that the persons, who express this delicacy, should
substitute a juster definition in its place. But for my part I must own
my incapacity for such an undertaking. When I examine with the utmost
accuracy those objects, which are commonly denominated causes and
effects, I find, in considering a single instance, that the one object
is precedent and contiguous to the other; and in inlarging my view
to consider several instances, I find only, that like objects are
constantly placed in like relations of succession and contiguity. Again,
when I consider the influence of this constant conjunction, I perceive,
that such a relation can never be an object of reasoning, and can never
operate upon the mind, but by means of custom, which determines the
imagination to make a transition from the idea of one object to that
of its usual attendant, and from the impression of one to a more lively
idea of the other. However extraordinary these sentiments may appear,
I think it fruitless to trouble myself with any farther enquiry or
reasoning upon the subject, but shall repose myself on them as on
established maxims.
It will only be proper, before we leave this subject, to draw some
corrollaries from it, by which we may remove several prejudices and
popular errors, that have very much prevailed in philosophy. First, We
may learn from the foregoing, doctrine, that all causes are of the
same kind, and that in particular there is no foundation for that
distinction, which we sometimes make betwixt efficient causes and causes
sine qua non; or betwixt efficient causes, and formal, and material, and
exemplary, and final causes. For as our idea of efficiency is derived
from the constant conjunction of two objects, wherever this is observed,
the cause is efficient; and where it is not, there can never be a cause
of any kind. For the same reason we must reject the distinction betwixt
cause and occasion, when supposed to signify any thing essentially
different from each other. If constant conjunction be implyed in what we
call occasion, it is a real cause. If not, it is no relation at all, and
cannot give rise to any argument or reasoning.
Secondly, The same course of reasoning will make us conclude, that there
is but one kind of necessity, as there is but one kind of cause, and
that the common distinction betwixt moral and physical necessity
is without any foundation in nature. This clearly appears from the
precedent explication of necessity. It is the constant conjunction of
objects, along with the determination of the mind, which constitutes
a physical necessity: And the removal of these is the same thing with
chance. As objects must either be conjoined or not, and as the mind must
either be determined or not to pass from one object to another, it
is impossible to admit of any medium betwixt chance and an absolute
necessity. In weakening this conjunction and determination you do not
change the nature of the necessity; since even in the operation of
bodies, these have different degrees of constancy and force, without
producing a different species of that relation.
The distinction, which we often make betwixt POWER and the EXERCISE of
it, is equally without foundation.
Thirdly, We may now be able fully to overcome all that repugnance, which
it is so natural for us to entertain against the foregoing reasoning,
by which we endeavoured to prove, that the necessity of a cause to
every beginning of existence is not founded on any arguments either
demonstrative or intuitive. Such an opinion will not appear strange
after the foregoing definitions. If we define a cause to be an
object precedent and contiguous to another, and where all the objects
resembling the farmer are placed in a like relation of priority and
contiguity to those objects, that resemble the latter; we may easily
conceive, that there is no absolute nor metaphysical necessity, that
every beginning of existence should be attended with such an object. If
we define a cause to be, AN OBJECT PRECEDENT AND
CONTIGUOUS TO ANOTHER,
AND SO UNITED WITH IT IN THE IMAGINATION, THAT THE IDEA OF THE ONE
DETERMINES THE MIND TO FORM THE IDEA OF THE OTHER, AND
THE IMPRESSION
OF THE ONE TO FORM A MORE LIVELY IDEA OF THE OTHER; we shall make still
less difficulty of assenting to this opinion. Such an influence on the
mind is in itself perfectly extraordinary and incomprehensible; nor can
we be certain of its reality, but from experience and observation.
I shall add as a fourth corrollary that we can never have reason to
believe that any object exists, of which we cannot form an idea. For as
all our reasonings concerning existence are derived from causation,
and as all our reasonings concerning causation are derived from
the experienced conjunction of objects, not from any reasoning or
reflection, the same experience must give us a notion of these objects,
and must remove all mystery from our conclusions. This is so evident,
that it would scarce have merited our attention, were it not to obviate
certain objections of this kind, which might arise against the following
reasonings concerning matter and substance. I need not observe, that
a full knowledge of the object is not requisite, but only of those
qualities of it, which we believe to exist.
SECT. XV. RULES BY WHICH TO JUDGE OF CAUSES AND EFFECTS.
According to the precedent doctrine, there are no objects which by the
mere survey, without consulting experience, we can determine to be the
causes of any other; and no objects, which we can certainly determine in
the same manner not to be the causes. Any thing may produce any thing.
Creation, annihilation, motion, reason, volition; all these may arise
from one another, or from any other object we can imagine. Nor will this
appear strange, if we compare two principles explained above, THAT THE
CONSTANT CONJUNCTION OF OBJECTS DETERMINES THEIR
CAUSATION, AND [Part I.
Sect. 5.] THAT, PROPERTY SPEAKING, NO OBJECTS ARE
CONTRARY TO EACH OTHER
BUT EXISTENCE AND NON-EXISTENCE. Where objects are not contrary,
nothing hinders them from having that constant conjunction, on which the
relation of cause and effect totally depends.
Since therefore it is possible for all objects to become causes or
effects to each other, it may be proper to fix some general rules, by
which we may know when they really are so.
(1) The cause and effect must be contiguous in space and time.
(2) The cause must be prior to the effect.
(3) There must be a constant union betwixt the cause and effect. It is
chiefly this quality, that constitutes the relation.
(4) The same cause always produces the same effect, and the same effect
never arises but from the same cause. This principle we derive from
experience, and is the source of most of our philosophical reasonings.
For when by any clear experiment we have discovered the causes or
effects of any phaenomenon, we immediately extend our observation to
every phenomenon of the same kind, without waiting for that constant
repetition, from which the first idea of this relation is derived.
(5) There is another principle, which hangs upon this, viz. that where
several different objects produce the same effect, it must be by means
of some quality, which we discover to be common amongst them. For as
like effects imply like causes, we must always ascribe the causation to
the circumstance, wherein we discover the resemblance.
(6) The following principle is founded on the same reason. The
difference in the effects of two resembling objects must proceed from
that particular, in which they differ. For as like causes always
produce like effects, when in any instance we find our expectation to be
disappointed, we must conclude that this irregularity proceeds from some
difference in the causes.
(7) When any object encreases or diminishes with the encrease or
diminution of its cause, it is to be regarded as a compounded effect,
derived from the union of the several different effects, which arise
from the several different parts of the cause. The absence or presence
of one part of the cause is here supposed to be always attended with
the absence or presence of a proportionable part of the effect. This
constant conjunction sufficiently proves, that the one part is the cause
of the other. We must, however, beware not to draw such a conclusion
from a few experiments. A certain degree of heat gives pleasure; if you
diminish that heat, the pleasure diminishes; but it does not follow,
that if you augment it beyond a certain degree, the pleasure will
likewise augment; for we find that it degenerates into pain.
(8) The eighth and last rule I shall take notice of is, that an object,
which exists for any time in its full perfection without any effect, is
not the sole cause of that effect, but requires to be assisted by some
other principle, which may forward its influence and operation. For as
like effects necessarily follow from like causes, and in a contiguous
time and place, their separation for a moment shews, that these causes
are not compleat ones.
Here is all the LOGIC I think proper to employ in my reasoning; and
perhaps even this was not very necessary, but might have been supplyd by
the natural principles of our understanding. Our scholastic head-pieces
and logicians shew no such superiority above the mere vulgar in their
reason and ability, as to give us any inclination to imitate them in
delivering a long system of rules and precepts to direct our judgment,
in philosophy. All the rules of this nature are very easy in their
invention, but extremely difficult in their application; and even
experimental philosophy, which seems the most natural and simple of any,
requires the utmost stretch of human judgment. There is no phaenomenon
in nature, but what is compounded and modifyd by so many different
circumstances, that in order to arrive at the decisive point, we
must carefully separate whatever is superfluous, and